Pandemic H1N1 influenza A viral infection complicated by atypical hemolytic uremic syndrome and diffuse alveolar hemorrhage.

We report here on a case of a 27-year-old man with atypical hemolytic uremic syndrome and diffuse alveolar hemorrhage associated with influenza A H1N1 infection. Treatment with oseltamivir, plasma exchange and hemodiafiltration for the hemolytic uremic syndrome and meticulous supportive care with steroid pulse therapy for the pulmonary alveolar hemorrhage was successful in this case. We discuss the relationship between hemolytic uremic syndrome and influenza A and the underlying immunologic factors that should be tested in a patient with atypical hemolytic uremic syndrome. We also discuss using steroid therapy for patients with H1N1-related diffuse alveolar hemorrhage.